BERRY GOOD PICKING : For the Best Purpled-Finger Experience, Olallieberries Are the Ones to Grow

Mention blackberries to any transplanted Easterner, and you'll elicit a flood of memories of berry-picking expeditions on warm summer days, of eating one's fill of the sun-ripened fruit and of the inevitable purpled fingers. Although wild-blackberry patches are scattered around the Southland, most of Southern California is prime growing area for the 'Olallie' berry, a magnificent, larger version with a flavor that surpasses that of the wild blackberry. Developed in Oregon, it grows best right here.

Viron Casey of Anaheim is a longtime gardener and berry fancier. So I knew when he asked me to come and look at his olallieberry patch last May that I would see something out of the ordinary. I found his vines blanketed with berries in all stages of ripeness. Casey picks an astounding 15 gallons of berries from only eight plants located in a compact, 5-by-18-foot section of his garden. Think of all those fresh, luscious berries and the pies, cobblers, jams, jellies, juice and ice cream toppings that you could make, and you'll soon be searching for a similar place in your garden.

It takes two years to establish a berry patch. The berries are produced on plants with roots and crowns that are perennial and will live for many years. However, the thorny canes (berry talk for the long stems that sprout from the base of the plant) are biennial, meaning they live only two years. The first year, these canes grow and then produce some laterals (side branches) late in the season, but no fruit. The second year, short branches emerge from buds on the laterals that do bear fruit.

'Olallie' plants are available in some nurseries during the winter or early spring. You can also get them from the Fowler Garden Center, 525 Fowler Road, Newcastle, Calif. 95658. Order the descriptive family-orchard booklet, for $2, or their mail-order price list, which is free of charge.

Olallieberries require support so put them in an area where they can be trained on a trellis. Casey grows his on a six-foot-high trellis and spaces the plants 2 1/2 feet apart. Most literature recommends spacing them six to eight feet apart, but Casey has had great success with the closer spacing, good news for gardeners who don't have half an acre out in back. His trellis is made of 2-by-4s, with a 1-by-2 running across the top as a brace. Three strands of clothesline wire are fastened horizontally underneath.

The soil should be well cultivated and enriched with organic materials and a light application of a fruit or vegetable fertilizer. Before setting the plants in the ground, cut the tops of the canes back to six inches. For each plant, make a planting hole in moist soil, and place the roots at a depth equal to that of the nursery container. Firm the soil around the plants.

During the first season, train the canes to sprawl over the trellis. The plants will go semi-dormant in winter; in January cut off all but six canes from each plant. Then trim the tips of the canes so that each one reaches only to the top of the trellis. Fan these out to blanket the structure and tie them to the wires so winter's winds don't blow them off. Each cane will produce a number of laterals that in turn will host the berries. Prune these side branches to 12 inches; this increases the size of the fruit.

The second year, the plants should bear a good crop, and new canes will appear that can be trained along the trellis or allowed to sprawl temporarily on the ground. After harvest, cut off all the old canes that have produced fruit; then the new canes can be tied to the trellis. In January of each following year, repeat the pruning and training process.

Olallieberries require ample moisture and should be watered weekly during the growing season. Using two pounds per 18-foot row of a 10-10-10 or similar fertilizer, feed them the first year in midsummer; in succeeding years, apply fertilizer in early spring, when foliage growth begins, and again in midsummer. Casey uses a liquid fertilizer on his plants with great success.

The berries begin to ripen in mid-May and continue for the next three weeks to a month. Well-tended, the plants produce for years, supplying you with all the fresh berries you can use plus a surplus to give to some very lucky friends and neighbors.